Conventional binders for magnetic recording media of the coating type include vinyl chloride-vinyl acetate copolymers, cellulose derivatives, acryl resins (i.e., copolymers of acrylic acid or methacrylic acid with their esters), polyurethane resins, vinylidene chloride copolymers, synthetic rubbers, polyesters and so on which have been prevailingly employed individually and in various combinations. In addition, there are also known a large nummber of binder compositions of the type which contain hydroxyl group-containing thermoplastic resins in combination with polyisocyanates to harden the films coated. However, surface properties excellent enough to be used in high density video tapes are not always attained with conventional methods and binder compositions as described in, for example, U.S. Pat. No. 4,135,016.